Sacred Groves are the fragments of a once existed forests, preserved over a period of times due to religious restrictions and taboos. They are often described as the sanctum sanctorum of a wide array of flora and fauna. These virgin forest patches often neglected by the floristic explorers and are usually remained unexplored for ever. They act as a reservoirs of many rare and threatened flora and fauna and also serve as a biodiversity hotspots protecting valuable genetic diversity. The work treats 531 species 5 subspecies and 20 varieties of flowering plants belonging to 398 genera and 112 families in the sacred groves spread across Thiruvananthapuram district of Kerala state, India. Each species is provided with its correct name, important synonyms, a brief taxonomic description, phenology, geographical distribution, etc to facilitate the readers to understand the species correctly. The book is the first of its kind in Kerala and would provide a model methodology for the floristic exploration in the sacred groves of any regions. It will be of immense use to the botanists, agriculturists, foresters, phytochemists, nature conservationists, etc.